An ear drainage culture is a lab test. This test checks for germs that can cause infection. The sample taken for this test can contain fluid, pus, wax, or blood from the ear.
A sample of ear drainage is needed. Your health care provider will use a cotton swab to collect the sample from inside the outer ear canal. In some cases, a sample is collected from the middle ear during ear surgery.
The sample is sent to a lab and placed on a special dish (culture media).
The lab team checks the dish every day to see if bacteria, fungi, or viruses have grown. More tests may be done to look for specific germs and determine the best treatment.
You do not need to prepare for this test.
Using a cotton swab to take a sample of drainage from the outer ear is not painful. However, ear pain may be present if the ear is infected.
Ear surgery is done using general anesthesia. You will be asleep and feel no pain.
The test may be done if you or your child has:
It may also be done as a routine part of myringotomy.
Note: Ear infections are diagnosed based on symptoms rather than using a culture.
The test is normal if there is no growth on the culture.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.
Abnormal results may be a sign of an infection. The infection can be caused by bacteria, virus, or fungus.
The test results may show which organism is causing the infection. It will help your provider decide on the right treatment.
No risks are involved with swabbing the ear canal. Ear surgery may involve some risks.
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.